Air-compressor.



No'. 678.431. Patenten my le. lem.

- E. H|L|..

AIR COMPRESSOR.

(App1c\tion led Apr. 19, 1901.) (No-Model.) 2 Sheets-Sheet l.

aZreeSe l n In yen? fiiorvfw 2/ TH: Nonms PETERS co, moro-urna..wnsmnn'mrl. n. c.

No. 678,487. Patented July la, lem. E. HILL. AIR COMPRESSOR.(Applicatie-n 'mea Apr. 19', 1901.)

2 sheets-'sheet 2.

(No Model.)

UNITED STATES PATENTQFFICE EBENEZER HILL, OF SOUTH NORWALK, CONNECTICUT.

AIR-COMPRESSOR.

SPECIFICATION forming part f Letters Patent N0. 678,487, dated July 16,1901.

Application led April 19, 1901.

To all whom t may concern,.- Be it known that I, EBENEZER HILL, acitizen of the United States, residing at South Norwalk, in the countyof Faireld and State of Connecticut, have invented certain new anduseful Improvements in Air-Compressors, of which the following is aspecification.

This invention relates to the means provided for keeping down thetemperature of air or gas being compressed, and while it is particularlyapplicable to three-stage compressors it may be adapted to single andtwo stage compressors.

The object of the invention is to so arrange the ducts that the air orgas in the chamberon the inactive side of a compressing-piston isobliged to flow through' a cooler before reaching the chamber on theactive side of a piston, thus insuring the cooling of all of the air orgas.

The embodiment of the invention that is illustrated has threecompression-cylinders with common valves and pistons, the Vfirst orlargest being double acting and the second or middle and the third orsmallest being single acting, with a duct leading from the chambers onthe active sides of the rst piston through a cooler to the chamber onthe active side of the second piston, a duct leading from the chamber onthe active sideof the second piston through a cooler to the chamber onthe active of the third. piston, and a duct leading from the chamberbetween the inactive sides of the second and third pistons andcommunicating with the duct from the irst cylinder before it passesthrough its cooler, as more particularly hereinafter described, andpointed out in the claims.

Figure 1 of the drawings is a side elevation showing the essentialfeatures of a threestage compressor with parts broken away to expose themechanism. Fig. 2 is an end elevation of the same compressor; andFig. 3is a view showing a single cylinder, piston, and cooler with a ductleading from the chamber on the inactive side of the piston andcommunicating with the cooling-duct before it ycompression-cylinder 9.

Serial No. 56,584 (No modela) The usual valves are so arranged that airor gas will enter this cylinder through the inletpipe 6 and be expelledthrough the outletpipe 7 at each stroke of the piston. This outlet-pipepasses through a cooler 8 of ordinary construction and is connected withthe chamber on the active side of the second This second cylinder hascommon valves so arranged that air or gas which enters is expelled onlyon the back stroke of the compression-piston 10, that by a rod 11 isconnected with the first compression-piston. A pipe 12 passes from thechamber onthe active side ofthe second compression-piston through anordinary cooler 13 tothe chamber on the active side of thecompression-piston 14 in the third compression-cylinder 15. Air or gasis expelled from the third cylinder through the outlet-pipe 16. Thethird compression-piston is connected by a rod 17 with the secondcompression-piston. The second compression-cylinder and the thirdcompression-cylinder communicate,

. and the active chambers are on opposite sides lof the pistons in thesecylinders-that is, air

or gas is compressed by the second piston on the back stroke andby thethird piston on the forward stroke. The chamber 18 between these pistonsis inactive. A pipe 19 leads from the passage 20, that communicates withthe chamber 18 between the inactive sides of the secondV and thirdpistons, tothe pipe that communicates with the first cylinder before thelatter pipe passes through the cooler 8, that cools the air or gas afterit has been compressed in the Iirst cylinder and is being forced to thesecond cylinder.

The compression-cylinders have common Water-jackets and an ordinarycirculating system 21, connecting the cylinder-jackets and the coolerswith the source of the cooling Huid. By these means air or gas is cooledin the cylinders while under compression and while flowing from. thechamber on the active side of one piston to the chamber on the activeside of the next piston. that ebbs and lows out of and into the chamberbetween the pistons is also cooled before it can pass to the chamber onthe active side of a piston and commingle with the air or gas to becompressed by that piston, for it must pass through a cooler.

The air or gas Ico Subjecting all of the air or gas both in thechamberson the inactive sides of the pistons as well as in the chambers on theactive sides of the pistons to the eiect of the cooling uid keeps thetemperature down to such an extent that it is not necessary to spray thecylinders and boxes containing the packings to prevent them frombecoming overheated.

The invention is not limited to a threestage compressor. The iirstcompressioncylinder could be omitted, if desired, and, as shown in Fig.3, the invention could be applied to a single-stage compressor. In thislatter form the single-acting piston 22 compresses air or gas in thecylinder 23 on the back stroke. The inlet-pipe 25 and outletpipe 26communicate with the chamber 24. The end of the cylinder is closed, soas to prevent the escape of air or gas that might leak past the pistoninto the chamber 27 on the inactive side of the piston, and this chamberis by a pipe 28 connected with the coolingduct before it passes throughthe cooler 29, so that air or gas that surges into and out of thechamber on the inactive side of the piston will be obliged to flowthrough the cooler before commingling with the air or gas that iscompressed in the cylinder.

The coolers may be any common construction, and if more than one is usedmay be arranged one above the other, as shown in Fig.

l, or side by side, as is common with many compressors of this nature.The cylinders shown are arranged tandem, although they might be arrangedparallel with one another.

The essential feature of this invention is the connecting of the chamberon the inactive side of a compressing-piston with a duct before thatduct passes through the cooler that keeps down the temperature of theair or gas being compressed.

The employment of this invention results in lowering the temperature ofthe air or gas under compression,and consequently decreasing thetemperature of the compressor parts. This increases the eiiiciency ofthe compressor and reduces the wear of the parts.

I claim as my inventionl. An air-compressor having a cylinder with asingle-acting piston, a cooler, a duct connected with the chamber on theactive side of the piston and extending through the cooler, and a ductconnecting the chamber on the inactive side of the piston with thecooler-duct before it passes through the cooler, substantially asspecified.

2. An air-compressor having cylinders with two single-acting pistons soarranged that the chambers on the inactive sides of the pistonscommunicate with each other, a cooler, a duct connected with the chamberon the active side of one of the pistons and extending through thecooler, and a duct connecting the communicating chambers on the inactivesides of the pistons with the cooler-duct before it passes through thecooler, substantially as specified.

3. An air-compressor having a plural number of cylinders with pistons,coolers, ducts connected with the chambers on the active sides of thepistons and extending through the coolers, and a duct connecting thechambers on the inactive sides of the pistons with acooler-duct beforeit passes through a cooler, substantially as specified.

4. An air-compressor having cylinders with a double-acting and twosingle-acting pistons, a cooler,- a duct connecting the chambers on theactive sides of the single-acting pistons and extending through thecooler, and a. duct leading from the chamber on the inactive sides 'ofthe single-acting pistons to the cooler-duct before it passes throughthe cooler, substantially as specified.

5. An air-compressor having cylinders with a double-acting and twosingle-acting pistons, a cooler, a duct connecting the chambers on theactive sides of the first piston with the chamber on the active side ofthe second pis# ton and extending through the cooler, a duct connectingthe chamber on the active side of the second piston with the chamber onthe active side of the third piston, and a duct leading from the'chamberbetween the second and third pistons to a. cooler-duct before it passesthrough a cooler,substantially as specified.

EBENEZER HILL.

Witnesses: l

E. HILL, Jr., HOWARD H. MossMAN.

